The influx of rack equipment in client/server, telecommunications process control, vibration monitoring, and numerous other electrical and electronic equipment environments has created a need for greater numbers of individual power branch circuits. These devices are smaller than the predecessors, more numerous, densely packed and consume less power. Because of this, most power distribution units expand their circuit breaker poles prior to exceeding their rated capacity. Present solutions to this problem require adding more electrical enclosures housing additional circuit breakers, or building larger, bulkier enclosures capable of housing the requisite additional breakers. As is evident, this requires additional space, expending the space available for additional electrical equipment and/or electronic components.
Available power distribution enclosures have a number of disadvantages that are particularly noticeable when a single enclosure having a large number of branch circuits is required. Prior art power distribution enclosures having a large number of branch circuits typically comprise frame structural cabinet and post members in addition to panel frame members that increase the size of the enclosure and limit the space avaiable for branch circuit panelboards. In addition, the installation of such enclosures in a raised floor environment typically requires that floor tiles be cut to allow cable entry. Such enclosures may also require the entire raised floor tile be removed and the enclosure set on the structural floor beneath causing a gapped space in the raised floor. Conversely, if the enclosure is too large it overlaps to adjacent tiles causing the inability to remove the adjacent tiles if needed. Yet another limitation of prior art designs is the lack of ability for users to have neat, easily accessible, and efficient installations because of numerous wires that extend from the enclosure branch circuits to the space under the raised floor.